Phototelegraphy



A. G. COOLEY PHOTOTELEGRAPHY July 2; 1929.

Filed Oct. 1925 2 Sheets-Sheet July 2, 1.9 9- A. G. COOLEY 1.719.392

PHOTOTELEGRAPHY Filed 001;. 1925 I 2 Sheets-Sheet ,2.

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.UNITED STATES PATENT OFFICE- aus'rm accomir, or CAMBRIDGE, MASSACHUSETTS, A ssIeNoR or FOR'1Y-NINE 01mnUNn Enrns 'ro cHA LEs c. HENRY, or STRAWBERRY rom'r, IOWA. f

rnoroTELEeRArnx.

Application filed October 9, 1925. Serial No. 61,441.

This invention relates to the art of phototelegraphy, and various parts of the subjectmat-ter-herein disclosed are claimed in my prior applications Serial Nos. 755,336 and 755,339, led on December 11, 1924, and my prior Patent N 0. 1,593,651, granted July 27, 1926.

. The principal objects of the invention are to provide a phototelegraphie system in which a series of printed messages, pictures or other subjects-matter may be transmitted successively'and automatically, and received in similar manner, preferably by producing relative movement between parts of the sender and receiver respectively in two dimen- 'sions and-synchronizing the senderand re ceiver movements in one dimension only.

Other objects of the invention will be apparent from the following description and claims, read in connection with the illustrative embodiments shown in the accompanying drawings, in which:

Fig. 1 is a diagrammatic representation of the mechanism at the-sending station; Fig. 2 is a section on line 2-2'0f Fig. 1; Fig. 3 is a plan view of a detail of the system shown in Fig. 1;

Fig. 4 is a diagrammatic representation of an illustrative form of receiving system; Fig. 5 is a plan View of a modification; and

Fig. 6 is a side view of the modification shown in Fig. 5. V I

Referring to Fig. 1, 1 represents a photoelectric cell connected to an amplifier 2- through a source of current 3 and in parallel with a resistance 4, 5 a second amphfier connected to the output circuit of the amphfier 2throughbatteries 6 and 7 and in paral-:

lel with a resistance 8, 9 a't-hird amplifier connected to the output side of amplifier 5 through a transformer. 10, and 11 a line coupled to the amplifier 9through transstation shown in Fig. 4. It will'be understood that as many amplifiers as desired may be used at the transmitting station and that the transmitter may be adapted either for line transmission or radio t-ransmission. Connected to the aforesaid circuit by transformer 13 is a source of alternating current 14' driven by motor. 15 at predetermined speed. Variation of the resistance of the photo-electriecelll in accordance with the subject-matter to be transmitted superimposes upon the grid of audion 5 potential variations which control the amplitude of the alternating current signals in line 11 originating at generator 14, thereby causing the receiving apparatus to reproduce the subject-matter all as described more fully in aforesaid Patent No. 1,593,651.

' According to this invention thesubjectss matter to be transmitted may -.-for example be mounted upon a conveyor belt 16 travelling over guide rollers 17 and 18 and driven by a motor 19 through either of twosets of gears 20 and 21. When transmitting telegrams for example, the printed tele rams are attached to the conveyor 16 and ed in succession past optical tracin or scanning means which moves transverse y of the path of the conveyor and focuses light from a .small spot of the subject-matter on the photo-electric cell. The telegrams may be attached tothe belt-vby means of clips 71 fast to the conveyor at opposite sides thereof, opposite sides of the telegram being slipped under these clips so that the tele-.

gram lies flat upon the conveyor. 7

The scanning. or tracing means may take any one of many forms but in the particular embodiment shown in Fig. 1 this means comprises a carrier 20 rotating about an axis extending'along the longitudinal center of the photo-electric cell 1. This carrier may 1 be drivenfrom motor 15 through gears'21' in sy'nchronism with the impulses transmitted to therline through transformer 13 from generator .14. The rotary carrier has four longitudinal arms 22 distributed 90 apart around the axis, of rotation and each arm .carries twolenses 23 and 24. Light source angular distance between the successive sets of lenses 23 and 24 being so determined that when the spot of light from one condenser lens 24 passes off the subject-matter at one ter from the opposite side of the conveyor.

side a spot of light from the next succeeding condenser lens 24 comes on the subject-mat- Inasmuch as the conveyor is moving slowly at approximately right-angles to the path of the lightspot the lines traced by succeeding spots of light, are substantially parallel and may beas close together as desired, depend-v ing upon the speed of rotation of the optical system and the rate of travel of the conveyor.

In order to hold the subject-matter in focus a support 26 is provided beneath the upper stretch of the conveyor belt, this support being curved transversely to position the subject-matter concentric with the axis of rotation of the o tical system, the conveyor belt being su ciently slack to conform to the curved support. In order to insure the subject-matter and conveyor slidingflsnugly along the support, the support may be hollow as shown in Fig. 2 and perforated on its uppler surface so that by pumping air from t e interior of the support as indicated by the arrow in Fig. 2 the belt 16 and subject-matter 27 are held in desired position as shown in Fig. 2, the belt being reticular when made of fabric for example. When using four sets of lenses as illustrated in Figs. 1 and 2, the curved subject-matter should subtend an arc of approximately 90 as shown in Fig. 2.

- transmitted the conveyor travels at increased In rder to increase the capacity of the appa tus'I prefer to provide means for increasing the speed of the conveyor between.

successivesubjects-matter. That" is, after each subject-matter has been completely speed until the next succeeding subject-matter comes-into position 'to be transmit ed. While various means may be emplciy to change the speed of the conveyor igs. 1

V and 4 illustrate two ways ase'xamp es. ,-The

means for varying the speed illustrated in Fig. 1 comprises two electromagnets 28 and 29 connected to an arm 30 pivoted at 31 and, engaging a clutch 32 kc ed to shaft 33 which drives-the conveyor be t. When magnet 28 is energized the-crutch 32 is thrown to the right to'conne'ct the conveyor to motor 19 through. {airs 21 810 1 L" en magnet 29 is energized the clutc 323s thrownto theleft thereby causing. the? conveyor to be driven rapidly.

thrfigh gears 20. The magnet 28 is con- 1160 In a circuit comprising battery 72 and a switch 35 which is closed momentarily as the clip 19, which holds the subject-matter -on'the conve or passes the switch as shown in'Fig. 2. e

- be closed at any'point along the length of the y positioning the subject-matter in predetermined relation to the" clips lengthwise of the conveyor this. switch niay telegram or, other subject-matter. Ordinarily the message or picture is so positioned that the switch is not closed until the body to drive the conveyor portion of the message is'about-to be traced by the optical system, although in the case of telegrams having headings they may be positioned so that the heading is transm1ttedas well as the body portion. In any event series with the output circuit of amplifier 9.

The tuned reed 35 of this relay is fixedly mounted at 36 and vibrates between contacts 37 and 38 under the influence of permanent magnet 39. As is well known, a tuned relay 75 The means illustratedin Fig. 1 for a'ctu' I l of this kind is only responsive to impulses of current transmitted to it at a predetermined frequency, at which time the reed vibrates, closing the circuit of electromagnet 29 through battery 40. The particular means illustrated in Figs. 1 and 3 for transmitting impulses of this predetermined frequency at the end of each message comprises a series of marks 41 (Fig. 3) extending transverselyof the conveyor at'the end of the subject matter system strong alternating current signal impulses are sent in groups of such' groug frequency as to actuate .the relay 34. hese impulses are also'transmitted over the line 11 to the receiving system to operate a similar mechanism at the receiving station as will be described hereinafter. Obviously a tunedcircuit might be employed instead of the tuned'relay 3 The receiving; apparatus illustrated diaammatically in Fig. 4 comprises a travel intg'conveyor and means for driving it at d" rent rates, this apparatus being similar to the corresponding apparatus at the transmitting station and the corresponding parts being similarly designated. As illustrated,

the means for increasing the speed of the conveyor at the end of'eachmessage may be like that" shown in Fig. 1, the relay 34' receiving the same impulses as the relay 34 in Fig. 1. However, the means for reducing the speed of the.receiving conveyor 16 at the beginning sions'comprises a switch 43 adapted to be of each successive transmisclosed at recurrent intervals by pins 44 mounted on the belt roller 18 at predetcr mined intervals, these pins recurrently closing theswitch 43 by wiping over, the projecting end 45 of one of the switch contacts. 1

The motors'19 and 19' at the transmitting. and receiving stations respectively are adapted to drive the belts atthe two stations at approximately the same speed. While they may be synchronized by any suitable l to be transmitted. Thesemarks are sospacedthat. when scanned by the optical amount depending upon the difference in speeds. The pins 44 on the roller 18 are spaced in accordance with the spacing of the successive messages on the conveyor at the transmitting station, the spacing between the pins 44 preferably being somewhat greater than the spacing between the messages at the transmitting station. Obviously the mechanism for varying the speed of the conveyor at the receiving station may be omitted en.-

tirely so that the receiving conveyor will either run 'cont-inuouslyor be stopped and started at the beginning and end of each message, as for example by two relays responsive to rows of dashes, such as 42 at the beginning and 41 end of each message fie reproducing mechanism shown in Fig. 4 is similar to that disclosed in my copending applications Serial Nos. 755,336 and 755,339. This mechanism comprises an amplifier A connected to a line 11 leading from the transmitting station (or in the case of radio to the detector circuit), another amplifier A connected to the output circuit of A anamplifier comprising an 'tllltllOll 46 connected to the amplifier A through transformer 47 the output circuit of 46 being connected through transformer-.48 to an oscillating circuit 49 which, as illustrated, mav be'of the well-known Hartley type. This oscillating circuit is connected through a Tesla transformer 50 tothe reproducer, which comprises contactpoints movable over the surface mounted on conveyer belt 16 upon which the subject-matter is to be reproduced. This reproduction is preterably effected by a corona discharge as disclosed in my prior application Serial No. 755,339. For this purpose four discharge needles or points 51 are mounted 90 apart on a rotating shaft 52 so that the needles ass in close juxtaposition to the reproducing surface mounted on the belt 16', the belt being curved transversely as described in connection with Figs. 1 and 2. A commutator 53 is mounted on'theend of the'shaft 52 so that the high frequency current through the Tesla transformer 50 passes to the needle 51 which is movin ac-ross'the belt; The reproducing surface ay be in the form of photographic paper or film attached to the belt16' in any suitable manner, and inasmuch asv the act-ion of the discharge on'thc photographic emulsion is largely if not en+ tirely electronic, the photographic emulsion may be enclosed within an envelope so that the apparatus may be used in the light. I

The synchronous apparatus for rotating the needles 51 in synehronism with the ro-- tati ng optical trains oi Fig. 1 may be of any 55. Also connected to the shaft 52 is the synchronizing motor 56 of the type disclosed in the aforesaid application, this'motor being connected to the line 11 through amplifiers A andA as in the prior application. In this way the synchronizing motor-56 sup-v plies advancing or retardingimpulses de rived from the generator 14 at the trans mitting station, to assist or oppose the eddycurrent'motor 54 dependngu-pon' whether the shaft 52 tends to run slower or faster than the rotating carrier 20 at the transmitting station.

The modification in Figs. 5 and 6 is intended to be used with a conveyor which need not be curved transversely as in Figs. 1. 2 and 3. In this modification the carrier 60 rotates about an axis perpendicular to the belt-'61 and carries its optical systems upon arms 62, each optical system comprising a light source 63 at the end of each arm and lenses 64 and 65 corresponding to 23 and 24 in Fig. 1'. The carrier 60 rotates around the photo-electric cell 66 and the parts are so adjusted that the light from the sources 63 traces the subject-matter on belt 61 in arcuate paths G7 concentric with the rotating will be provided t o.prevent variation of light being tra-nsmittedto the photo-electric cell except by the particular optical system which is tracing the subjectqnatter, and only while that particular system is crossing the belt, suitable means for screening the photoelectriccell from the undesirable light maycomprise opaque-coatings on the photo-electric cells having windows 69 and 70, (Figs. 1 and 6 respectively).

From the foregoing it will be evident that the operation of the system is as follows:

The subjects-matter tobe transmitted are.

clipped to the belt*16- somewhere between the roller 17 and table 26 and are unelipped and' removed after passing the table. So far as this invention isconcerned anyisuita-ble means may be'employed to attach and deceiving stations are adjusted to drive the roller '18 without using a belt. The mtors 19 and 19 at the transmitting andreconveyors at approximately the same rate and the needles 51 are synchronized with the optical systems 2324.-, in accordance with' the frequency of the impulses transmitted to the line by the generator 14 as above described. The amplitude of these impulses is varied-in accordance with the subject-matter to be transmitted by varying the potential ofthe grid of audion 5 under .the control,of the photo-electric cell as more fully described in myprior application Se-7 rial No- 755,336. These impulses of Vargt 6 mg amplitude control the intensity of discharge from needles 51 to reproduce the subject-matter. At the end of each message the two relays 34 and 34' increase the speed .in response to the row of marks 41 (Fig.3):

of the subject matter. At the beginning of the negzt'subject -m'atter the speed of the con-' veyer at the transmitting station is again reduced by the automatic closing of switch 35.

At the receiving station the speed of the conveyer is reduced at the same time as the transmittingconveyer, or somewhat sooner,

' jects-matter may by the automatic closing of switch 43. Thus a series of messa es, pictures or other sub- Tae transmitted continually and automatically without synchronizing the conveyor at the transmitting and receiving stations respectively, although of course it will be understood that .these conveyers may be synchronized if desired. When using a continuous reproducing sheet at the receiving station, as for instance photographing paper or film, the receiving conveyer is perfectly stopped between messages, Suitable mechanism .forthis purpose may for example comprise magnets-28 and 29 controlled by tuned relays to respond to definite frequenciesrespectively and the mescontinuously vfeeding subject-matter along a sages to be transmitted ha'vin marks of different spacing" at the beginning and end so I only to the marks at the beginning of the, message, while the relay 28 responds only' that-the relay controlling 29' will respond to the marks at the end of the. message as above described. Where the conveyer is to be stopped between messages the ears 21'- would of course be omitted. In t e illustrated embodiment the messages are preferably reproduced on separate sheets and spaced along the receiving conveyer'thesame as the sub'ects-m'atter to be transmitted are distribute along the transmitting conveyer.

From the foregoin'git will be evident that the relative movement in two-dimensions'between'parts of the senderand receiver respectively is synchronized in onedimension only, the rotary movement of the optical systems at the transmitting station bein synchronized with the rotary'movemento the recordin points at the receiving station without sync roni'zing the movements of the Iconveyers at the two stations, thereby sim- .Iplifying the s stem without substantially afr fecting its e ectiveness.

1. In a phototelegraphic system, sending means responsive to the subject-matter to be transimtted, conveyor means for continu-. ously feeding spaced subject-matter into op-. 8 erative association with said sending means,

and means for automatically increasing the speed of the conveyor-1 while the spaces between' predetermined parts of the. subject-- matter are passing the sending means.

2. A phototelegraphic :systemcomprising I a sender including point-by-point' tracing means for tracing thesubject-matter along substantially parallel; paths with' an o tical system focused upon'a photo-electric cel and automatic means for successively bringing recurrent subjects-matter into the ath' ofsaid tracing means, whereby SIICCGSSIVB subjects may be transmitted continually and automatically. 3. A phot'otelegraphic system comprising a sender including .point-by-point. tracing. means for tracing the-subject-matter' along substantially rallel paths with an o tical system foc'u -upon a photo-electric cel and a oonve or for -continually feedingsubjectsmatter into-the ath of said tracing means with said versely of t e conveyor. 4. In a phototelegraphic system, -a sender including means for tracingthe subject-matter alon substantially parallel paths. with a beam 0 light, a'conveyor ffor continually feeding subjects-matter in {spaced relation into the path of said tracing beam, and means for automatically increasing the speed of the conveyor while the'spaces between. the-subjects-inatter are the tracing beam.

5. In a photote' egraphic system,fmeansfor T continuously feeding along a predetermined path subjects-matter spaced on 'tudinallyj; of the ath, means for continua ly tracing,

the sub ect-matter from, side tojaide with an ml el paths extending trans- 7 6:11; a phototelegraphie system, means for optical system swingingtransversely through an arc, and means for increasing the speed of the feeding means while the spaces between said subjects-matter pass the light rays.

In a phototelegraphic system, transmitting' means for continuously feeding along a predetermined path subjects-matter spaced longitudinally of the path, means for continually tracing the subject-matter from side to side by means swinging transversely through an are, receiving means continually movable along a predetermined path for recording the transmitted subjects-matter, and means for varying the speed of said trans mitting and receiving means between successive subjects-matter.

8. In a phototelegraphic system, transmitting means for continuously feeding along a predetermined path subjects-matter spaced longitudinally of the path, means for continually tracing the subject-matter from side to side by means swinging transversely through an are, receiving means continually movable along a predetermined path forvrecording the transmitted subjects-matter, and

' means controlled by the transmitting means for varying the speed of said transmitting and receiving means between successive subjects-matter.

9. In a phototelegraphic system, transmitting means for continuously feeding along a predetermined path subjects-matter spaced longitudinally of the path, means for continually tracing the subject-matter from side to side by means swinging transversely through an are, receiving means continpally movable along a predetermined path for recording the transmitted subjects-matter, means controlled by the-'transmitting'means for increasing the speed of said transmitting and receiving means at the end of each subject-matter, and means controlled by the transmitting means for decreasing the speed of the transmitting means before the transmission of the next subject-matter.

10. In a phototelegraphic'system, transmitting means for continuously feeding along a, predetermined path subjects-matter spaced longitudinally o the path, means for continually tracing the subject-matter from side to, side by means swinging transversely through an arc,rece1v1ng means continually movable along a predetermined path for, recording vthe transmitted subjects-matter,

means controlled by the transmitting means I for increasing the speed of said transmitting ject-matter,

and receiving means at the end of each suband means controlled by the receiving means for decreasing the speed of the receiving means before the transmission I of the next subject-matter.

11. In a phototelegraphic system, sending means responsive to the subject-matter to be transmittgd, conveyor means for continuously feeding spaced subjects-matter i'nto operative association with said sending means, and means responsive to movement of the conveyor for automatically increasing the speed of theconveyor while the spaces between the subjects-matter are passing the.

sending means. 4

12. In a phototelegraphic system, a sender including means for tracing the subject-matter along substantially parallel paths with a beam of light, a conveyor for continually feeding subjects-matter in spaced relation into the path of said tracing beam, and means responsive to movement of the conveyor for automatically increasing the speed of the conveyor while the spaces between the subjects-matter are passing the tracing beam.

13. In a 'phototelegraphic. system, means for continuously feeding along a predetermined path subjects-matter spaced longitudinally of the path, means for continually trac; ing the subject-matter from side to side with an optical system swinging transversely 'through an arc, and means responsive to mined path subjects-matter spaced longitudinally of the path, means for continually tracing the subject-matter from side to side with means swinging transversely through an arc, and means for increasing the speed of the feeding means .wh1le the spaces between said subjects-matter pass the tracing means. v

16. In a phototelegraphic system, sending means responsive to the subject-matter to be transmitted, conveyor means for continuously feeding spaced subjects-matter into operativefassociation with said sending means, and means responsive tomarks on the subjects-matter for varying the speed of the conveyor while the spaces between the subjects-matter are passing the sending means.

17. In a phototelegraphic system, a sender including means for tracing the subjectmatter along substantially parallel paths, a conveyor for continually feedingsubjectsmatter in spaced relation'into the path of the trace, and means responsive to marks on the subjects-matter for varying the speed of the conveyor while the spaces between the subjects-matter are passlng the tracing means.

. 18. In a phototele raphic system, means for continuously fee ing along a predeterinined ath subjects-matter spaced lo tudinal y of the path, means for continua ly tracing the subject-matter from side to side with means swinging transversely through an arc, and means responsive to marks on the subjects-matter for varying the speed of g the conveyor while the spaces between the subjects-matter are passing the tracing means. 4

19'. In a phototelegraphic system, transmitting means for continuously feeding along a predetermined path subjects-matter versely vfor continually spaced longitudinally of the path, means tracmg the subject-matter from side to slde by means' swinging transtinual y movable along a predetermined path for recording the transmitted sub ectsmatter, and means responsive to marks on the subjects-matter for varying the speed of saidtransmitting and receiving means between successive subjects-matter.

20. In a phototelegraphlc system, transmitti'ng means for continuously feeding along a predetermined path subjects-matter spaced longitudinally through an arc, receiving means conmatter.

matter, and means responsive to marks on.

. the subjects-matter for varying the speed of said transmitting and receiving means between successive SubJectS-matter.

21. In a phototelegraphic' system, transmittin'g means for continuously feeding along a predetermined ath subjects-matter spaced longitudinally o the path, means for continually tracing the subject-matter from side to side by means swinging transversely through an are, receiving means continually movable along a; predetermined path for recording the transmitted subjects-matter, means responsive to marks on the subjectsmatter for increasing the speed of said transmitting and receiving means at the end of each subject-matter, and means controlled by the transmitting means for decreasing the speed of the transmitting means before the transmission of the next subject Signed by me at Rutherford, New this sixth day of October, 1925. AUSTIN G. 'GOOLEY. 

